Edge grinding machine



Oct. 20, 1936. 1 T. G. WRIGHT ESGE GRINDING MACHINE .Filed April 20, 1935 3 'Sheets-Sheet 1 INVENTOR. Tf-/of/:HGG WRIGHT By. N @D A TTORNEYS.

Oct. 20, 1936. T. G. WRIGHT 2,057,809

EDGE GRVINDING MACHINE Filed April 20, 1935 3 Sheets-Sheet 2 IN VEN TOR. 77-oMns WR l GH -r Bgm@ 'f/aw A TORNEYS.

Oct. 20, 1936.v I" AT, G. wRiGH-r 2,057,809

EDGE GRINDING MACHINE Filed April 2o, 1955 3 'sheets-sheet :5

IN V EN TOR. THOMHJ G. WR IGH T l BYWYQEA/ A TTORNEYS.

Patented Oct. 20, 1936 UiTED STATES PATENT OFFICE EDGE GRINDING MACHINE Application April 20, 1935, Serial No. 17,480

4 Claims.

The invention relates to machines for grinding the curved edges of glass plates of sheets, such as are employed in automobile bodies, and the machine is adapted to grind either sheets of ordinary plate or window glass or laminated sheets, ordinarily referred to as safety glass. The invention is illustrated as applied to grinding the edges of a number of sheets at one time, but it will be understood that single sheets may be edged if desired. The invention has for its objects the provision of a machine of simple construction, which may be easily loaded and unloaded; which provides a secure support for the glass sheets so that vibration and any breakage incident thereto is reduced to a minimum; and which permits one grinding wheel to be used with two sheet handling cradles, so that the wheel may be utilized to its full capacity. Certain embodiments of the invention are illustrated in the accompanying drawings, wherein:

Figure 1 is a side elevation. Fig. 2 is a section on the line II-II of Fig. l. Fig. 3 is a plan view of a part of the apparatus, the view being taken along the line III-III of Fig. l. And Fig. 4 is a section on the line IV-IV of Fig. 1.

Referring to the drawings, the base upon which the machine is mounted consists of the parallel side channels I, I, the lcross channels 2, 2, `and the end members 3, 3, preferably in the form of castings. At the center of the base is a standard 5 built up of plates on which is mounted the bearings 6, 6, which carry the axle 'l :of the grinding wheel B. This wheel is provided with a plurality Yof grooves, so that a plurality of glass sheets may be edged or ground at the same time.

Mounted pivotally upon the end castings 3, 3, as indicated at 9, 9, is a pair of similar arms I0, II upon which are mounted the supports or cradles in which the glass sheets to be edged are supported. These arms and the apparatus carried thereby are similar throughout so that a description of one will serve for both. The framework of the arm lconsists of a pair of parallel channels I2, I2 secured together by suitable transverse ties, such as the channels I3, I3 and by the plates I4 and I5. The arms are moved up and down in order to bring the glass plates into and out of engagement with the grinding wheel by means of the air cylinders I6 and II pivoted at the base of the machine at i8 and provided with the plungers I9 p'ivotally connected to the arms, as indicated at 20. When the arms are in lowered or grinding position, no air is applied in the cylinders, so that the arms float, being maintained in such position only by gravity.

In order to counterweight the arms, suitable balancing Weights 2I, 2l are secured to the arms outward of the pivots 9, 9. These weights are so adjusted that the glass sheets engage the periphery of the grinding wheel with the degree of pressure necessary for the most efcient grinding eiect. driven from an electric motor 22 mounted upon the base of the machine, and provided with a pulley 23 around which passes the belt 24, such belt also extending around a suitable pulley 25 on one end of the shaft l. The wheel is, in operation, supplied with water by means not shown and is partially surrounded by the guard 26, which acts as a collector for the surplus water.

Mounted on the plate I5 at the free end of the arm II is the oscillating work holder or cradle, in which the plurality of glass plates 2l that are to be ground, are supported. This cradle consists of a plate 28 secured rigidly to the end of a shaft 29, which shaft is mounted for oscillation in a pair of bearings 30, 30 secured to the plate I5. The shaft 29 carries at its end the spur gear 3l and this gear is driven through suitable gearing from a motor 32 carried on the plate I4. This gearing includes the belt 33, reduction gearing in the casing 34, and the pinion 35 which meshes with the gear 3|.

The plate 28 is provided with a plurality of sets of slots 36, 3l and 33, in which are mounted Ysuitable grooved means for engaging the edges of the sheets 2l and holding them in proper position in alignment with the grooves in the grinding wheel during the grinding operation. As Shown, the slots 36 and 38 carry a pair of grooved rubber rolls 39 and 4D, mounted on shafts or rods 4I and 42 which extend through the slots and are clamped in position by means of nuts 43. The slots 3l carry a block 44 having at one end a plurality of spaced lingers 45 and at the other end a grooved rubber roll 45 similar to the rolls 39 and 42. This block is clamped in position by means of bolts 4l provided with nuts 48. The arrangement of grooved rolls in connection with the fingers 45 provides a means for supporting the glass plates 2l on three sides, and this support may be adjusted to suit plates of dierent sizes and shapes due to the plurality of slots employed in the plate 28.

As shown in Fig. l, the arm Il and its cradle are in loading position, and during the loading of this cradle, the grinding operation is being carried out on the other arm I0, the cradle on this last arm being shown in the position occupied when the first step of the grinding operation The grinding wheel is preferably.

is completed. After the operator has slipped the plates 21 into the cradle 28 (between the rolls 39 and 42 and against the roll 46) from the left hand end with the parts occupying the position shown in Fig. 1, the air is released from the cylinder Il, and the arm Il is moved downuntil the grinding wheel engages the glass sheets at the point marked X.

At this time the motor 22 is driving the grinding wheel in a counterclockwise direction, while the motor 32 is driving the cradle about its axle 29 in a counterclockwise direction, as indicated by the arrow. The action of the grinding wheel upon the glass plates tends to move them to the left between the grooved rolls 39 and i, andl in order to resist thismovement and to steady the plates against Vibration, a fourth grooved roll 49 is employed, such roll being of rubber and carried upon a bracket 50, pivoted to the plate 28 at 5|. The bracket and roll are together of suicient Weight to prevent any movement of the glass plates to the left during the grinding operation. It is necessary, however, to withdraw the roll 49 from the glass edges during the concluding portion ofthe grinding operation, and to accomplish this object, a stop 52 is employed Which Y .engages the end of the bracket 50 and prevents its further downward movement, as the cradle swings around to nal position similar to that occupied by the glass plates carried by the cradle on the arm I0.

`During this last period of grinding, the holding action of th'e roll 49 is no longer required in order to maintain the glass plates in proper position. After this final position is reached, the motor 32 is reversed and the cradle swung back to its starting position, thus exposing the edges of the plates to a second grinding or smoothing Voperation. The glass plates may now be removed vfrom the cradle and a new set of plates inserted for a'second grinding'operation. During this period of reloading,.the cradle carried on'the other arm l0 is operated togrind a set of sheets so that the grinding wheel is utilized to its fulll capacity, the period forunloading and reloading the cradle approximating in length the grinding period. It will be understood that the grinding operation on the plates in one cradle is completed before ythe grinding of the other plates is started, and that the direction of rotation of the grinding wheel is reversed'for the two sets of plates;

In positioning the glass plates upon the cradle, they are arranged so that the axle 29 comes as nearly as possible to the center of the arc of curvature of the edge which is to'be ground, although this is not essential and the arc. is often of vchanging radius. The machine is capa- .ble of handling plates of a wide variety of sizes and having edge curves of widely varying radius.

vWhat I claim is:

l. In combination in a machine for grinding the curved edges of glassplates, a grooved driven grinding wheel mounted for rotation about a horizontal axis, a cradle for supporting a glass plate in a vertical position above the wheel, an arm to which the cradle is pivoted on a horizontal axis for rocking movement to carry the curved edge of the glass plate over the grinding wheel, a pivotal support for the arm at one side of the grinding wheel about which the arm swings freely during the grinding operation, a motor on the arm and driving connections between the motor and cradle for rocking the cradle.

2. In combination in a machine for grinding the curved edges of glass plates, a grooved driven grinding wheel mounted for rotation about a horizontal axis, a cradle for supporting a glass plate in a vertical position above the wheel, an arm towhich the cradle is pivoted on a horizontal axis for rocking movement to carry the curved edge of the glass plate over the grinding wheel, a pivotal support for the arm at one side of the grinding Wheel about which the arm swings freely during the grinding operation, a motor on the arm, driving connections between the motor and cradle for rocking the cradle, and means for moving said arm about its pivotal support to move the glass plate into and out of engagement with the grinding wheel.

3. In combination in a machine for grinding the curved edges of glass plates, a grooved driven grinding wheel mounted for rotation about a horizontal axis, a pair of cradles each of which is adapted to support a glass plate in a vertical position above the wheel on opposite sides of a vertical plane extendingv through the axis of rotation of the grinding wheel, arms on opposite sides of thewheel on which the cradles are pivoted on horizontal axes for rocking movement to carry the curved edges of the glass plates over the grinding wheel, pivotal supports for the arms at opposite sides of the wheel about which the arms swing freely during the grinding operation, and a rnotory on each arm arranged to rock the cradle carried thereby.

4;. In combination in amachine for grinding Ithe' curved edgesgof glassplates, aV grooved driven grinding wheel-V mounted for lrotation about a horizontal axis, a pair of cradles each of which is adapted to 'support a glass plate in a vertical position aboveY the wheel on opposite sides of a vertical plane extendingthrough thel axis of rotation o f the grindingwheel, arms on opposite sides of the wheel on. which the cradles are pivoted on horizontal axes for rocking movement to carry the curved edges of the glass plates over the grinding wheel; pivotal supports for the arms at opposite sides of the Vwheel about which the arms swing freely during the grinding operation, a motor on each arm arranged to rock the cradle carriedrthereby, and means for moving the arms abouttheir pivotal supports to move the glass plates carried by the cradles into Aand out of engagement with'the grinding wheel.

THOMAS G. WRIGHT.` 

